Nonlinear numerical investigation of buckle propagation in subsea pipelines

When a cylindrical shell buckles under hydrostatic pressure, the buckling propagates along the pipe, developing a post buckling phenomena which causes a progressive structural failure. The existing design approaches are conservative giving approximately 1.5-2 times the collapse values, therefore finding the real values can lead to the optimum design. In this research, numerical modelling of buckling propagation has been investigated. A finite element modelling of the pipe has been conducted by ANSYS software invoking nonlinearities both in material and geometry. The finite element models are based on the data from the experiments conducted at the Structures Laboratory of The University of Queensland. The results obtained from the nonlinear modelling are in a reasonable agreement with those achieved in the experiments